Blender file from Blender 2.49 to 2.79 when rendering changes default screen layout
This is a wild step in the dark since I haven't used 2.49 in quite a while. But there's two things you can try.


Make a new file and append the data you need from the other file with SHIFTF1. That way you should be able to isolate pretty well what is broken and what isn't.
You can disable 'Load UI' when loading the old file.